Large well bore drilling apparatus



Dec. 26, 1967 Y C. R. CANALIZO LARGE WELL BORE @BILLING APPARATUS 2 Sheets-Sheet l Filed Oct. 8. 1964 www ATTORNEYS Dec. 26, 1967 c. R. cANALlzo 3,360,061

LARGE WELL. BoRE DRILLING APPARATUS Filed Oct. 8, 1964 v 4 f 2 Sheets-Sheet 2 Carlos RCan'olizo BY @www ige INVENTOR l United States Patent O f 3,360,061 LARGE WELL BORE DRILLING APPARATUS Carlos R. Canalizo, Las Vegas, Nev., assignor to Otis Engineering Corporation, Dallas Tex., a corporation of Delaware Filed Oct. 8, 1964, Ser. No. 402,425 17 Claims. (Cl. 175-324) This invention relates to well apparatus and more particularly to a well apparatus for drilling a well bore and transporting to the surface earth cuttings and liquids flowing into the well bore.

An object of this invention is to provide a new and improved well apparatus for drilling a well bore and transporting to the surface the earth cuttings produced during the drilling and any liquid flowing into the well bore through a tubular member or tubing which extends from the bottom of the well bore to the surface.

Another object is to provide a well apparatus of the type described having means for accelerating the movement of the cuttings and liquids through the longitudinal passage of the tubular member at longitudinally spaced locations along the tubing by introducing or injecting gas at high velocity into the tubing in the direction of longitudinal movement of the fluids therethrough.

Still another object is to provide a well apparatus for drilling a well bore and for transporting cuttings Iand liquid from the well bore which provides for circulation of low pressure gas into the well bore and then upwardly through the tubing extending through the well bore and for the circulation of high pressure gas from the surface through a passage means extending about the tubing and into the tubing to `aid in the transport of the cuttings and liquids to the surface.

A further object is to provide a well apparatus of the type described wherein a drill is secured to the lower end of a drill pipe which provides the passage for the circulation of high pressure gas and wherein means are positioned adjacent the drill for maintaining the liquids and cuttings at the bottom of the well bore in a state of agitation or turbulence to facilitate their movement into the lower end of the tubing.

A still further object is to provide a well apparatus of the type described wherein the agitating means includes a baille means extending downwardly of the drill adjacent the drill face and means for directing jets of gas at the drill face immediately in front of the baiiie means.

Another object is to provide a well apparatus of the type described wherein the tubing is provided at vertically spaced locations with control 'devices for controlling the ow of the high pressure gas into the tubing from the annular gas passage between the tubing and the drill pipe through which the tubing extends.

Still another object is to provide a well apparatus of the type described wherein high pressure gas from the gas passage is directed against the bottom of the well bore below the drill to agitate the cuttings and liquids in the well bore.

Still another object is to provide a well apparatus of the type described wherein the rate of flow of high pressure gas from the gas passage directed against the bottom or' the well bore is controlled by controlling the effective orifices of the passages through which the high pressure gas flows from the gas passage.

Still another object is to provide a well apparatus having the flow control device responsive to the pressure within the gas passage for permitting flow of gas from the gas passage through nozzles adjacent the drill face of the well bore only when the pressure in the -gas passage is raised to a predetermined value.

Additional objects and advantages of the invention wil-l 3,360,061 Patented Dec. 26, 1967 be readily apparent from the reading of the following description of a device constructed in accordance with the invention, and reference to the accompanying drawings thereof, within:

FIGURE 1 is a schematic illustration of a drilling apparatus for drilling a well bore .and for transporting liquids and cutting from the well bore;

FIGURE 2 is an enlarged fragmentary schematic View, partly in section, of the drill bit and the means for agitatin-g the cuttings at the drill face of the apparatus illustrated in FIGURE l;

FIGURE 3 is a bottom schematic view of the apparatus illustrated in FIGURE 2;

FIGURE 3-A is a schematic illustration of the baffle means and the means for directing jets of gas at the drill face;

FIGURE 4 is a schematic fragmentary sectional view of a modified means for mounting the roller bits of the drill bit on the drill bit body;

FIGURE 5 is a vertical, partly sectional View of the upper portion of a flow control device used in the apparatus;

FIGURE 6 is a View similar to FIGURE 5 being a continuation thereof showing the lower portion of the ow control device;

FIGURE 7 is a schematic sectional illustration of a modified form of the drilling and agitating apparatus of the invention;

FIGURE 8 is a bottom schematic view of a drill having a modified form of the bathe;

FIGURE 9 is a schematic illustration of the baille means and the means for directing jets of gas at the drill face of the drill illustrated in FIGURE 8; and,

FIGURE l0 is a bottom schematic view of drill havin-g a modified form of the means for directing jets at the drill face and agitating the earth cuttings.

Referring now to FIGURE 1 of the drawing, the well apparatus 20 for drilling a large diameter well bore 21 utilizes the circulation of gas to remove the cuttings of the earth formation produced by a usual drill 22 on the bottom end of the usual drill pipe 23, and any liquid flowing into the well bore as during the drilling ofl the,

well bore in locations where the well bore extends through a porous water bearing formation 24. The drill pipe 23 extends through a suitable casing head 25 secured to the upper end of a casing 26 which extends a short distance into the ground. The casing head has an inlet conduit or pipe 27 which opens to the annulus or gas passage 28 about the drill pipe so that large volumes of air of relatively low pressure may be introduced or pumped into the upper end of the large annulus and iiow at relatively low velocity to the bottom of the bore and then upwardly through a string of tubing 30 at an increased velocity to carry the cuttings of the earth formations penetrated by the drill and any liquids iiowing into the well bore to the surface. The tubing extends through the drill pipe 23 and and a gear 36 on a drive shaft 37 driven by any suitable prime mover. A

The drill pipe at its upper end portion extends rotatably through a suitable Imanifold -38 and is provided with a plurality of ports 39 which open to the annular passage 40 of the manifold. The manifold has -an inlet pipe or conduit 42. Gas under high pressure is introducible'into the upper end of the gas passage 44 between the tubing and the drill pipe by means of the manifold and the ports of the :drill pipe. The upper end of the gas passage is closed by a suitable packer or seal" 45 which seals between the tubing and the drill pipe. A suitable closure or packing 47 which seals between the string of tubing and the drill pipe closes the bottom end of the gas passage.

The string of tubing has a plurality of flow control devices or ejector pumps 50a, b, c, connected therein at longitudinally spaced locations which control the flow of gas from the gas passage into the string of tubing to aid in transporting cuttings and liquids from the bottom of the well bore through the tubing to the surface. Each of the ejector pumps includes a tubular mandrel threaded as at its upper and lower end portions whereby it may be connected by the usual coupling collars 61 to adjacent ends of adjacent sections of the tubing and may constitute a section of the tubing.

A cylindrical sleeve 64 is disposed about the mandrel intermediate its ends and includes a tubular bottom section 65 rigidly secured to the mandrel in seal tight relationship therewith by a weld 66. A tubular charge chamber section 67 of the sleeve has a lower end portion telescoped over the reduced end portion 68 of the bottom sleeve section and is rigidly secured thereto in seal tight relationship by a weld 69. The upper end portion of the chamber sleeve section telescopes over the reduced lower end portion 70 of a connector section 71 of the sleeve and is -rigidly secured thereto in seal tight relationship by a weld 72. A tubular port section 74 of the sleeve is telescoped downwardly over the upper portion of the connector section with its downward movement limited by the engagement of its annular bottom end shoulder sur- -face with the upwardly facing annular shoulder 75 of the connector section. The port sleeve section has a plurality of lateral ports 76 intermediate its ends. The top section 77 of the sleeve has a reduced lower end portion 78 telescoped into the upper end portion of the port sleeve section and rigidly secured thereto in seal tight relationship by the weld 79. Thev port and top sections of the sleeve are held against upward movement on the mandrel by a retainer ring 80 threaded on the upper end portion of lthe mandrel and rigidly secured in any adjusted position against rotation by a set screw '81. The bottom annular end surface of the retainer ring abuts the upper end surface ofthe top sleeve section.

The top sleeve section has a pair of internal annular recesses in which are disposed O-rings 84 which seal between the top section and a seal ring 85 rigidly secured to in seal tight relationship with the mandrel by a weld 86.

The mandrel 60 and the sleeve 64 define an annular space about the mandrel closed at the upper and lower ends by the bottom and top sleeve sections and separated into a lower annular charge chamber 91 and an upper iiow passage 92 by a resilient tubular closure `or valve member 93. The valve member is disposed within the sleeve and about the upper inner support portion 94 of the connector sleeve section which is spaced inwardly of a port sleeve section. The lower end portion of the valve member has an internal rigid bottom ring 95, which -rnay be bonded thereto, which telescopes over the annular external surface 96 of the connector sleeve section below its circumferentially spaced lateral ports 97. The lower end portion of the valve member is compressed against and sealingly engages the internal annular surface of the port sleeve section below its downwardly facing annular shoulder 98 and is thus held against upward displacement. An O-ring 99 disposed in an external annular recess of the connector sleeve section seals between the bottom ring of the valve member and the connector section.

A top ring 100 is similarly disposed in the upper end portion of the valve member and may be bonded thereto. The upper end portion of the valve member telescopes iuto the enlarged lower portion 101 of an annular support 102 and is compressed against and sealingly engages the internal surfaces of the outer support member defining the enlarged portion. An O-ring 103 disposed in an external annular recess of the inner support portion 94 seals between the ring 100 and the support portion. The upper end of the support portion of the connector sleeve section is rigidly secured to, and in seal tight relationship with, the mandrel by a weld 104. The outer support member is secured to the support portion 94, by any suitable means, as by a set screw 105.

The inner support portion 94 and the outer support member 102 hold the lower portions of a tubular resilient check valve 106 therebetween, the outer support member having internal annular recess 107 in which is received an external annular tiange 108 of the check valve. The upper annular lip portion 109 of the check valve is engageable with the internal surfaces of the port sleeve section to prevent downward ow through the annular ow passage 92 4to the ports 76. The lip portion resiliently flexes inwardly to permit flow of uids from the ports 76 and through the circu-mferentially spaced longitudinal slots 110 of the outer support member and thus through the flow passage 92.

Fluid under pressure is introducible into the charge chamber 91 through a suitable filler valve 112 threaded in an enlarged intermediate portion of the liller passage 113. A protector plug 114 is threaded in a lower enlarged portion of the passage to protect the valve.

It will be apparent that the force of the charge of compressed gas in the chamber 91, communicated to the internal surface of the valve member intermediate its ends through the radial ports 97 of the connector sleeve section, biases the valve'member 93 outwardly toward expanded position and into sealing engagement with the internal surface of the port sleeve section about its lateral ports 76 to close the ports to inward iiow of uids therethrough, and that the valve member will be moved inwardly to its retracted or open position to open the ports when the pressure exteriorly of the valve member exceeds the pressure in the chamber 91.

The mandrel 40 above the check valve 106 has a plurality of circumferentially spaced inwardly extending apertures in which are disposed tubular inserts 121. The upper end portions 122 of the bores or passages of the inserts flare upwardly, i.e., increase in diameter upwardly. The lower enlarged threaded portions of the passages open to the passage 92 above the check valve. Beans 124 having orifices 125 are threaded in the lower portions of the inserts. The orifices of the beans communicate with the passage 92 and the flared upper portions 122 of the passages of the inserts. The rate of ow of gas from the passage 92 into the internal longitudinal passage or bore 126 of the mandrel, at any given pressure of the gas in the flow passage 92, may -be adjusted by providing beans of different orifices. The inserts 121 and the beans 124 are preferably made of a very hard wear resistant substance to minimize their flow cutting by the gas owing therethrough.

The upper ends of the passages of the inserts open to the inner longitudinal passage 126 of the mandrel below the lower end of an annular passage restricting member 130 rigidly secured by the screws 131 in the enlarged upper end portion of the longitudinal passage. The bottom end of the passage restricting member is disposed immediately above the annular upwardly facing shoulder 132 of the mandrel and the lower upwardly and inwardly extending internal surface 133 of the restricting member at its lower end is of substantially the same diameter and ush with the internal surface of the mandrel defining the passage 126 below its shoulder 132 to minimize turbulence in gases flowing upwardly through the restricting member. The restricting member also has an intermediate central cylindrical surface 134 and an upwardly and outwardly extending upper internal surface 135.

Due to the restriction of the flow passage of the mandrel above the top ends of the passages of the inserts, gas flowing into the mandrel through the inserts increases in velocity. The pumping or ejector action of the gas injected into the mandrel from the gasfpa-ssage 44, whose effect is intensified by the restriction of the mandrel ow passage 126 immediately above the top ends of the flow passages of the inserts 121, tends to move fluids in the tubing upwardly to the surface. The restricting member 130 is preferably hard surfaced to resist abrasive wear and, since it extends into the passage of the mandrel, it tends to prevent wear of the mandrel since the main ow of fluids bearing earth cuttings is thus spaced inwardly of the internal surfaces of the mandrel. The restricting member is easily replaced when worn to an excessive degree.

If the apparatus is to be used in drilling a well bore through earth formations which produce liquids at relatively great rates which flow into the well 'bore being drilled by the apparatus, the pressure of the charge of gas in the charge chamber of each of the ejector pumps 50a5tlc connected in the string of tubing 30 is so selected that the pressure charge in each pump is lower than that in the pump next above it in the well bore 21, the lowermost ejector pump 50c having the lowest charge pressure and the uppermost ejector pump 50a having the greatest charge pressure. Thus, as the pressure of the gas in the gas passage 44 rises as it is introduced or pumped into the gas passage through the inlet conduit 42, the ejector pumps are opened progressively and successively, the bottom ejector pump 50a opening first, then the next higher ejector pump 50b and then the uppermost ejector pump 55e. If the well bore is to penetrate earthformations which produce no or little water, the pressures in the cha-rge chambers of the several ejector pumps are prefera-bly set at equal values.

It will be apparent that while only three ejector pumps have been shown connected in the string of tubing 30, the number of valves and their spacing is determined by the particular requirements of a particular well bore being drilled, which may vary with the characteristics of the earth formations which the well bore penetrates, the rate of drilling, the rate of flow of liquids into the well bore, and other such factors.

The drill 22 secured to the lowerend of the drill pipe 23 may include a suitable body 150 which has suitable support means -by means of which the usual earth and fragmenting roller bits 151 are rotatably mounted on the body. The roller bits are arranged below the bottom surface 153 of the body in a suitable pattern to overlap the full area of the well bottom or drill face F of the well bore as the drill is rotated. The lower end of the string of tubing extends downwardly through the closure or packing 47 and through a central downwardly opening bore or aperture 155 of the drill lbody. The 'bore 155 opens toa laterally outwardly extending and downwardly opening recess 156 of the body in which is positioned a baffle or scoop 158 rigidly secured to the lower end of the string of tubing and whose elongate opening or throat 169 extends substantially radially across substantially the full radius of the bore hole. The scoop, of course, opens as at 161 to the lower end of the longitudinal passage of the tubing. The scoop is provided with a downwardly opening recess 167 in which is rotatably mounted in any suitable manner, one of the roller bits 151. The roller bits are so arranged that during each complete rotation of the drill the full area of the drill face F will be engaged by the drill and the earth formation is fragmented thereby in the usual manner.

A substantially horizont-al manifold or nozzle duct 170 is also disposed in the recess 156 and is supplied with compressed gas under high pressure from the gas passage 44 =by means of the duct 171 which extends through a suitable aperture in the closure 0r packer 47 and which is rigidly secured to the drill body. The manifold is provided with a plurality of `spaced nozzles 174 through zles 174 are directed downwardly in the direction of the scoop.

The tubing immediatelyabove the drill and the closure or packing 47 is provided with a plurality of upwardly convergent passages 180 which may be ared upwardly in the same manner as the passages 122 of the inserts 121.

In use, when the well apparatus 20 is lused to drill a large diameter well bore, -for example, four or more feet, large volumes of air under relatively low pressure are introduced into the annulus 28 through the duct or pipe 27 and flow downwardly to the bottom of the well bore at relatively low velocity and then enter into the bottom end of the tubing 30 through the throat 160 of the scoop. The velocity of ow of the gas as it flows into the tubing increases greatly since the effective orifice of the tubing is much smaller than the eective orifice of the annulus 2S. Cuttings from the earth formations being fragmented by the roller bits of the drill as the drill rotates and any small amounts of liquid in the bore are readily transported to the surface through the tubing by such gas introduced under relatively low pressure into the well bore at the surface as long as no appreciable amounts of water flow into the well at the bottom of the well bore, as due to the penetration of the drill through a water bearing formation, such as the -water bearing formation 24, or as long as the rate of production of the earth cuttings does not exceed the transport capacity of the low pressure gas.

If water or cuttings tend to accumulate at the bottom of the well bore, gas under Irelatively high pressure is introduce into the `gas passage 44 at the surface through the pipe 22 and the manifold 38. As the gas under high pressure is introduced into the gas passage at the surface it commences to flow downwardly through the duct 171 and manifold 170, and jets of high velocity gas are directed at the drill face or bottom of the well bore to place such cuttings and any water in the bore into agitation or turbulence and therefore flow more readily through the scoop throat into the bottom of the tubing and thence to the surface instead of settling on the bottom of the -well bore. At the same time the gas ows upwardly through passages into the tubing immediately above the d-rill and this lgas flow also aids in lifting such cuttings and water to the surface.

If the well bore is to penetrate through earth forma'- tions which produce no liquids at relatively low rates the charges of gas in the charge chambers of the several ejector pumps are set at the same pressure and, if cuttings tend to accumulate in the Well bore, the pressure of the gas in the gas passage is increased to the value at which the ejector pumps are rendered operative and gas under high pressure, for example 450 p.s.i flows through the ejector pumps into the flow passage of the tubing to further aid in transporting the cuttings and any small amounts -of water to the surface. As the drilling of the well bore is now continued, the'operation of the ejector pumps and of the jets of gas from the nozzles 174 in cooperation with the scoop '158 aid in transporting the cuttings and water flowing into the well tothe surface through the tubing.

It will be apparent that during the rotation of the drill the scoop causes turbulence at the bottom of the well bore which turbulence is increased by the action of the jets of ai-r from the nozzles 174.

If the well bore is to penetra-te earth formations which.

produce liquids at relatively great rates, the pressures of the charges of gas in the charge chambers of the ejector pumps are set at progressively lower values with their depth in the well, the charge pressure of the lowest ejector pump being the smallest.

If water accumulates in the well bore and in the tubing to a height above any of one or more of the ejector pumps, for example, the scecond lowermost ejector pump 50h, upon the introduction of gas under high pressure into the gas passage, the pressure in the gas passage is increased first to the value at which the bottom ejector pump 50c is rendered operative and gas under high pressure flows through the ejector pump in -to the flow passage of the tubing and lowers the pressure in the tubing below the location of ejection of the gas into the tubing through the bottom ejector pump. As the pressure in the gas passage continues to increase, the next lower ejector pump Sb and then the ejector 50a are rendered operative. As the ejector pumps 50c and 50b are rendered operative, the gas from the gas passage begins to flow into the tubing beneath the column of water in the tubing below the passages 122 of the inserts 120 of the ejector pump Stic and then of the pump 50b and lifts the column or slug of water thereabove upwardly through the tubing. If necessary, the pressure of the gas in the gas passage is increased to the value at which the top ejector pump is also rendered operative. The gas owing into the tubing through the ejector pumps then aids in transporting the water and cuttings from the well bore to the surface. The pressure in the gas passage is maintained at such pressure as required to render and then maintain operative the smallest number of ejector pumps necessary to remove any accumulation of water and cuttings from the well bore and then prevent any more accumultaion to minimize the amount of gas which must be pumped into the gas passage. The upward movement of the slug of water is, of course, accelerated by the pump action of the top ejector pump 50a until the slug of water flows upwardly and out of the upper end of the tubing. The fiow of gas at high velocity through the lowermost ejector passages 180 and through the nozzles 174 also aids in transporting the water to the surface.

When any such water which has accumulated in the well bore and tubing has been removed to the surface, the action of the iiow of low pressure gas into the well bore through the pipe 27 at the surface may be effective to transport any water which may continue to ow into the well bore and cuttings as they are produced to the surface in which event the introduction of the high pressure gas may be discontinued or it may be introduced into the gas passage at a relatively low pressure, higher than the pressure which is lower than that necessary to open any of the ejector pumps, but sufficiently great to cause jets of air to flow through the nozzles 174 and the ejector passages 180. If such combined flow of high pressure gas merely through the ejector passages 180 and the nozzles and of the low pressure gas is not eective to transport the Water and cuttings to the surface through the tubing, the pressure of the gas in the gas passage is increased to the value necessary to cause operation of such number of the ejector pumps 50 as may be necessary to transport the cuttings and the water to the surface.

The turbulence or agitation of the cuttings at the drill face varies, of course, with the rate of ow of gas between the bottom surface 153 of the drill body and the drill face and such agitation increases for a given rate of flow of the low pressure gas into the annulus yand of the high pressure gas through the nozzles 174 as the distance between the bottom surface 153 of the drill body and the drill face decreases. As is illustrated in FIGURE 6, this distance may be decreased by providing the bottom of the drill body with relatively deep downwardly facing recesses 183 in which upper portions of the roller bits y8 151 may be received. The roller bits are, of course, rotatably mounted, as by means of pinions or shafts 183 which are journaled in suitable bores of the body which open into the recesses 182.

The scoop serves as a baffle, as well as a scoop, since it moves over the drill face and also agitates the water and cuttings. In addition it also provides a bathe or barrier to the horizontal flow of the high pressure gas as the jets of gas are deected from the drill face thus further increasing the turbulence.

In the event that the water flows into the well ybore at the same rate as it is being removed from the well bore, a layer of water may form a seal between the well bore and the bottom of the tubing passage in which case, the low pressure gas does not flow from the well bore into the tubing and the pressure in the well bore is then merely maintained at a predetermined low pressure.

In some cases if the cuttings tend to accumulate in a dry well bore, water may be introduced through into the well bore to help wash the cuttings away from the roller bits and toward the passage of the tubing. If desired the viscosity of the water flowing into the well bore from earth formations or introduced thereinto at the surface may be increased by the addition thereto of suitable substances such as gels, soap and the like, to increase the cuttings transportation capability of the water.

The well apparatus 200 iilustrated in FIGURE 7 is similar to the apparatus 20 and, accordingly, elements of the well apparatus 200 have been provided with the same reference numerals, to which the subscript a has been added, as the corresponding elements of the well apparatus 20. The body 201 of the drill bit 202 is rigidly secured to the lower end of the drill pipe 23a and a plurality of conical drill -bits 151a, only three of which are shown, are rotatably mounted on the body below its bottom surface 153a by means of suitable shafts 204. The lower end of the tubing 30a, in which one or more of the ejector pumps 50 are connected, extends through a reduced bottom portion of the bore of the drill body 201 which provides a seal surface 205. Downward movement of the tubing in the casing is limited by the engagement of its bottom annular downwardly facing shoulder 206 with the upwardly facing stop shoulder 207 of an internal annular ange 208 of the drill body.

A flow control device 210, mounted in the string of tubing immediately above the drill, is similar to the flow control devices 50 having a flexible valve member 211 which is biased outwardly into sealing engagement with the internal surfaces of a sleeve 212 by the force of a charge of compressed gas in a charge chamber 213 to close the lateral ports 215 of the sleeve and prevent ow of the gas from the gas passage 44a between the string of tubing and the drill pipe into the flow passage 217 and past the tubular check valve 218 to the exterior of the tubing. The passage 217 opens outwardly into an annular passage 220 between the tubing and the drill pipe between the upper and lower packers or seal means 223 and 224 mounted on the tubing and sealingly engaging the internal seal surface 205 of the drill body. The tubing has ejector passages 227 which permit flow of gas from the passage 220 into the string of tubing in an upward direction. The drill body also has passages 229 which open to the passage 220 and to the well bore below the face 153er through suitable nozzles 230 which direct jets of the gas inwardly and downwardly at the drill face or bottom of the well bore.

It will be apparent that the well apparatus 200 will function in the same manner as the well apparatus 20 to aid in transporting cuttings and liquids owing into the well bore to the surface through the tubing 30a.

xIt will be apparent that the ow of the high pressure gas from the gas passage 44a is controlled by the flow control device 210, the pressure of whose charge of gas in its charge chamber 213 may be higher than the pressure intthe charge chambers of any of the ejector pumps con- 9 nected in the tubing 30a thereabove. The ow control device 210 will open to permit flow of the high pressure gas into the tubing through the ejector ports or passages 227 and to the well bore through the passages 229 and nozzles 230 only after the ejector pumps in the tubing have successively opened.

As a result, any column of water which may have accumulated in the well bore and in the string of tubing is raised by the successive openings of the ejector pumps connected in the string of tubing 30a. When the column or slug of water above each of the ejector pumps has been lifted to the surface, the pressure of the gas in the gas passage 44a is increased to the value which exceeds the pressure of the charge of gas in the charge chamber 213 of the tiow control device 210, the valve member 211 is moved to its open position and the high pressure gas ows from the gas passage through the lateral ports 215 and the passage 217 into the annular passage 220 and thence through the ejector ports 227 of the tubing to raise any column or slug of water in the tubing thereabove. At the same time the high pressure gas flows through the nozzles 230.

It will thus be apparent that one of the main differences between the well apparatus 20 and the well apparatus 200 is that the flow of high pressure gas through the ejector ports 180 and the nozzles 174 of the well apparatus 20 commences whenever gas is introduced into the gas passage 44a at the surface whereas in the well apparatus 200 the ow of gas through the lowermost ejector ports 227 and the drill nozzles 230 takes place only after all of the ejector pumps connected in the string of tubing thereabove have opened and the pressure in the gas chamber is increased to a predetermined value.

Alternatively, the pressure of the charge of gas in the charge chamber 213 of the liow control device may be lower than the pressure in the charge chambers of any of the ejector pumps 30a connected thereabove. In this case, the flow of high pressure gas through the ejector parts 227 and the nozzles 230 of the apparatus 200 commences when the pressure in its gas passage is raised to a predetermined value and the ejector pumps will be rendered operatively only if the gas pressure in the gas passage is raised above such predetermined value and to the values at which the ejector pumps are rendered operative.

It will now be seen that the new and improved well apparatus for drilling a well bore and transporting from the well bore cutting and liquids flowing into the well bore to the surface includes a stringl of tubing which extends about the drill pipe on which the drill is mounted, a plurality of ejector pumps connected at longitudinally spaced locations in the string of tubing, a bafe or scoop 158 through whose open throat 160 the cuttings and liquid enter into the bottom end of the tubing, and a means for agitating the cuttings and liquids which may be present between the bottom surface of the drill body and the drill face of the well bore which includes means such as the nozzles 174 or 230 through which a gas from the annulus or gas passage between the tubing and the drill pipe is ejected at high velocity downwardly at an angle at the drill face and in the direction of such bafe or scoop.

It will further be seen that the flow of high velocity gas may take place immediately upon introduction at the surface of the high pressure gas into the gas passage between the tubing and the drill pipe or in the well apparatus 20 if, as in the well apparatus 200, the` apparatus is provided with the ilow control device 210 only after the pressure in the gas passage has been raised toa predetermined value.

It will further be seen that the well apparatus 20 as well as the well apparatus 200 has ejector passages opening upwardly into the tubing adjacent its lower end whereby any column of water between such ejector passages and the lowermost ejector pump thereabove may be lifted by the gas owing through the ejector passages. If desired, a passage restricting member, such as the member of the ejector pumps, may be mounted in the tubing above such ejector passages.

It will further be seen that the rear vertical wall 160a of the scoop extends angularly outwardly relative to the radius of its rotation in the direction of rotation whereby its rotation tends to move any cuttings engaged thereby radially inwardly toward the center and toward the lower end of the tubing.

Referring now particularly to FIGURES 8 and 9 of the drawing, the drill 22a is substantially similar to the drill 22 and, accordingly, its elements have been provided with the same reference numerals, to which the subscript a has been added, as the corresponding elements of the drill 22. The scoop 158e of the drill 22a differs from the scoop 158 of the drill 22 in that it is open at the bottom and is provided with a resilient batlie strip 300 rigidly secured as by bonding, or the like to the trailing side of the scoop 158:1 and which extends below the scoop toward the drill face F. The jets of high velocity gas from the nozzles 174a tend to agitate and are directed downwardly at such angle toward the drill face that they deect from the face F in the direction of the bottom open end of the scoop and thus tend to agitate and carry the cuttings into the scoop and thus into the tubing.

Referring now to FIGURES 10 and 11 of the drawing, the drill 22b is similar to the drill 22 and accordingly its elements have been provided with the same reference numerals, to which the subscript b has been added as the corresponding elements of the drill 22. The body b of the drill 22b has a plurality of nozzles 302 at circumferentially spaced locations which are supplied with high pressure gas from the gas passage of the well apparatus through suitable passages or ducts 303 which extend through the drill body 150b. The jets are inclined downwardly and inwardly toward the lower end of the scoop 15819 connected to the lower end of tubing. The scoop has a downwardly and outwardly flared annular ange 304 spaced below the bottom surface of the drill body 150b so that the velocity of the gas ilowing into its lower end is increased due to the narrow spacing therebetween. The jets of high velocity gas from the nozzles 174b are directed inwardly and downwardly at such an angle that when deflected from the drill face they are directed towards the open lower end of the scoop and thus also tend to aid in moving the cuttings into the throat of the scoop.

The drill bits 151 and 151:1 are each usable with the drill body of either form of the drill.

It will now be apparent that several forms of a drill having a bafile and a means for agitating the cuttings produced by the drill have been illustrated and described.

It will further be seen that while a particular ejector pump has been illustrated and described as being connectable in the string of tubing for controlling the flow of high pressure gas from the gas passage o-f the apparatus into the tubing through which the cuttings and liquids from the bottom of the well bore are transported to the surface that the tubing may be provided with other types of ow control devices which permit ow of high pressure gas therethrough from the gas passage into the tubing. For example, valves of the type described and illustrated in Patent No. 2,954,043 may be mounted on the exterior of the tubing in the manner described in the patent, in circumferentially spaced relationship, and in the gas passage, at suitable vertically spaced locations therealong for controlling the How of gas from the gas passage into the tubing through suitable ports thereof.

It will further be seen that while the apparatus is pros vided with a means, such as the well head 25 and the coriduit 27, for introducing air under relatively low pressure into the well bore, in certain installations the well bore may be open to the atmosphere at the surface and the transport of the cuttings and liquids from the well bore through the tubing is then effected by the operation of the ejector pumps connected in the tubing.

The foregoing description of the invention is explanatory only, and changes in the details of the construction illustrated may be made by those skilled in the art, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A well apparatus for drilling a well bore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatable drill pipe having a drill on its lower end; means closing the upper end of the well bore through which the drill pipe extends movably; means for introducing gas under low pressure into the well bore about said 'drill pipe; 4a tubing extending longitudinally through said drill pipe and spaced therefrom to .provide an annular gas passage therebetween, said tubing having a longitudinal passage opening at its bottom end to the well bore below said drill and opening at its upper end to the surface, said longitudinal passage being of substantially smaller orifice than the annular passage of the well bore about the drill pipe whereby air introduced at low pressure into the well bore at the surface ows downwardly to the bottom of the well bore .at a low velocity and then upwardly Iat an increased velocity through said longitudinal passage to transport liquids and cuttings of earth formations being penetrated by sai'd drill to the surface; means closing the upper and lower ends of said gas passage; means for introducing gas at relatively high pressure into the upper end of said gas passage; downwardly inclined jet oriiice means mounted on said drill for directing jets of gas from sai'd gas passage into the well lbore below said drill downwardly toward the bottom of the well bore and toward the longitudinal passage of said tubing; and ilow directing means on the drill directing ow of gas and cuttings upwardly into the longitudinal passage of the tubing.

2. A well apparatus for drilling a web bore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatable drill pipe having a drill on its lower end; means closing the upper end of the well bore through which the -drill pipe extends movably; means 4for introducing gas under low pressure into the well bore iabout sai-d drill pipe; a tubing extending longitudinally through said drill pipe and spaced therefrom to provide an annular gas passage therebetween, said tubing having a longitudinal passage opening at its bottom end to the well bore below said drill and opening at its upper end to the surface, said longitudinal passage being of substantially smaller oritice than the annular passage of the well bore about the drill pipe whereby air introduced at low pressure into the well bore 'at the surface flows downwardly to the bottom of the well bore at a low velocity and then upwardly at an increased velocity through said longitudinal passage to transport liquids :and cuttings of earth formations being penetrated by said drill to the surface; means closing the upper and lower ends Of said gas passage; means for introducing gas at relatively high pressure into the upper end of said gas passage, said tubing having at least one ow control valve device connected thereto for controlling introduction of gas from said gas passage into said longitudinal passage and directing the flow of the gas upwardly into said longitudinal passage to increase the velocity of upward flow of uids through said longitudinal passage.

3. A well apparatus for drilling a well lbore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatable drill pipe having a drill on its lower end; means closing the upper end of the well bore through which the drill pipe extends movably; means for introducing gas under low pressure into the well `bore about said drill pipe; a tubing extending longitudinally through said drill pipe and spaced therefrom to provide an annular gas passage therebetween, said tubing having a longitudinal passage opening `at its bottom end to the well bore below said drill and opening at its upper end to the surface, said longitudinal passage being of substantially smaller orifice than the `annular passage of the well bore about the drill pipe whereby air introduced 'at low pressure into the well bore at the surface ows downwardly to the bottom of the well bore at a low velocity and then upwardly .at an increased velocity through said longitudinal passage to transport liquids and cuttings of earth formations being penetrated by said drill to the surface; means closing the upper and lower ends of said gas passage; means for introducing gas iat relatively high pressure into the upper end of said gas passage, said drill including a body having a bottom surface and a plurality of earth fragmenting means mounted on said body below said bottom surface for engaging the bottom of the well bore; a baille projecting downwardly of said bottom surface and extending outwardly of the centr-al axis of said drill from a point adjacent and communicating with the lower open end of the tubing; and means on said body for directing jets of gas from said gas passage into the well bore downwardly and in the direction of said baille and the open end of the tubing.

4. A well apparatus for drilling a well bore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatable drill pipe having a drill on its lower end; means closing the upper end of the well bore through which the drill pipe extends movably; means for introducing gas under low pressure into the well bore about said drill pipe; a tubing extending longitudinally through said drill pipe and spaced therefrom to provide an annular gas passage therebetween, said tubing having a longitudinal passage opening at its bottom end to the well bore below said drill and opening 'at its upper end to the surface, said longitudinal passage being of substantially smaller orifice than the annular passage of the well bore about the drill pipe whereby air introduced at low pressure into the well bore at the surface flows downwardly to the bottom of the well bore at a low velocity and then upwardly at an increased velocity through said longitudinal passage to transport liquids and cuttings of earth formations being penetrated by said drill to the surface; means closing the upper and lower ends of said gas passage; means for introducing gas at relatively high pressure into the upper end of said gas passage, said tubing having at least one flow control device connected thereto for controlling admission of gas from said gas passage into said longitudinal passage and directing the flow of the gas upwardly into said longitudinal passage to increase the velocity of upward flow of fluids through said longitudinal passage; said drill including a body having a bottom surface and a plurality of earth fragmentin g means mounted o n said body below said bottom surface for engaging the bottom of the well bore; a baffle projecting downwardly of said bottom surface and extending outwardly of the central axis of said drill from adjacent the lower open end of said tubing; Iand means on said body for directing jets of gas from said gas passage into the well bore downwardly and in the direction of the baille to be directed by the baflle into the lower open end of the tubing.

5. A well apparatus for drilling a well bore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatable drill pipe having a drill on its lower end; means closing the upper end of the well bore through which the drill pipe extends movably; means for introducing gas under low pressure into the well bore about said drill pipe; a tubing extending longitudinally through said drill pipe and spaced therefrom to provide an annular gas passage therebetween, said tubing having a longitudinal passage opening at its bottotm end to the well bore below said 4drill and opening at its upper end to the surface, said longitudinal passage being of substantially smaller orifice than the annular passage of the well bore about the drill pipe whereby air introduced at low pressure into the well bore at the surface flows downwardly to the bottom of the well bore at a low velocity and then upwardly at an increased velocity t-hrough said longitudinal passage to transport liquids and cuttings of earth formations being penetrated by said drill to the surface; means closing the upper and lower ends of said gas passage; means for introducing gas at relatively high pressure into the upper end of said gas passage, said drill including a body having a bottom surface and a plurality of earth fragmenting means mounted on said body below said bottom surface for engaging the bottom of the well bore; a baie projecting downwardly of said bottom surface and extending outwardly of the central axis of said drill from adjacent the lower open end of said tubing; and means on said body for directing jets of gas from said gas passage into the well bore downwardly and in the direction of said baille to be directed by the baffle into the lower open end of said tubing, said tubing having inlet passages opening upwardly thereinto from said gas passage adjacent the lower end of said tubing and at spaced points thereabove.

6. A well apparatus for drilling a well bore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatable drill pipe having a drill on its lower end; means closing the upper end of the well bore through which the drill pipe extends movably; means for introducing gas under low pressure into the well bore about said drill pipe; a tubing extending longitudinally through said drill pipe and spaced therefrom to provide an annular gas passage therebetween, said tubing having a longitudinal passage opening at its bottom end to the well bore below said drill and opening at its upper end to the surface, said longitudinal passage being of substantially s-maller orifice than the annular passage of the well bore about the drill pipe whereby air introduced at low pressure into the well bore at the surface flows downwardly to the bottom of the well bore at a low velocity and then upwardly lat an increased velocity through said longitudinal passage to transport liquids and cuttings of earth formations being penetrated by said drill to the surface; means closing the upper and lower ends of said gas passage; means for introducing gas at relatively high pressure into the upper end of said passage; said tubing having inlet passages opening upwardly thereinto` adjacent said drill from said gas passage; flow control valve means in said inlet passage controlling admission of gas through said inlet passages into said tubing; and means mounted on said drill for directing jets of gas from said gas passage into the well bore below said drill downwardly toward the bottom of the Well bore and toward the loweropen end of the tubing.

7. A well apparatus for drilling a well bore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatable drill pipe having a drill on its lower end; means closing the upper end of the well bore through which the drill pipe extends movably; means for introducing gas under low pressure into the well bore about said drill pipe; a tubing extending longitudinally through said drill pipe and spaced therefrom to provide an annular gas passage therebetween, said tubing having a longitudinal passage opening at its bottom end to the well bore below said drill and opening at its upper end to the surface, said longitudinal passage being of substantially smaller orifice than the annular passage of the well bore about the drill pipe whereby air introduced at low pressure into the well bore at the surface ows downwardly to the bottom of the well bore at a low velocity and then upwardly at an increased velocity through said longitudinal passage to transport liquids and cuttings of earth formations being penetrated by said drill to the surface; means closing the upper and lower ends of said gas passage; means for introducing gas at relatively high pressure into the upper end of said gas passage, said drill including a body having a bottom surface and a plurality of earth Afragmenting meansmounted on said body below said bottom surface for engaging the bottom of the well bore; and a scoop having an elongate throat opening substantially radially outwardly below said bottom surface, and to said longitudinal passage of said tubing.

8. A well apparatus for drilling a well bore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatable drill pipe having a drill on its lower end; means closing the upper end of the well bore through which the drill pipe extends movably; means for introducing gas under low pressure into the well bore about said drill pipe; a tubing extending longitudinally through said drill pipe and spaced therefrom to provider an annular gas passage therebetween, said tubing having a longitudinal passage opening at its bottom end to the well bore below said drill and opening at its upper end to the surface, said longitudinal passage being of substantially smaller orifice than the annular passage of the well bore about the drill pipe whereby air introduced at low pressure into the well bore at the surface flows downwardly to the bottom of the well bore at a low velocity and then upwardly at an increased velocity through said longitudinal passage to transport liquid and cuttings of earth formations being penetrated by said drill to the surface; means closing the upper and lower ends of said gas passage; means for introducing gas at relatively high pressure into the upper end of said gas passage, said drill including a body having a bottom surface and a plurality of earth fragmenting means mounted on said body below said bottom surface for engaging the bottom of the well bore; and a scoop having an elongate throat opening substantially radially outwardly below said bottom surface, and to said longitudinal passage of said tubing; and means on said body for directing jets of gas from said gas passage downwardly of said bottom surface and in the direction of said scoop.

9. A device for use in a well bore drilling apparatus including: a drill having a body securable to a drill pipe, said body having a bottom surface; a plurality of earth engaging and fragmenting means mounted on said body and extending downwardly of said bottom surface; a scoop having a substantially radially opening throat opening below said bottom surface, said body having a central aperture for receiving a bottom end portion of a tubing, Said scope communicating with said tubing receivable in said central aperture; and means communicating with an annular passage providable by said tubing and said drill pipe connectable to said body for ejecting jets of gas from said passage below said bottom surface downwardly and in the direction of said throat, said scoop directing said jets of gas into said central aperture.

lt). The device of claim 9 wherein said tubing adjacent said body is provided with a plurality of radially spaced inwardly and upwardly opening ejector passages through which gas from said annular passage may flow upwardly into said tubing adjacent said body.

11. The device of claim 10, and means responsive to the pressure in said passage for controlling flow of gas from said passage to said means for ejecting jets of gas and said ejector ports.

12. A well apparatus for drilling a well bore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatable drill pipe having a drill on its lower end; means closing the upper end of the well bore through which the drill pipe extends movably; means for introducing gas under low pressure into the well bore about said drill pipe; a tubing extending longitudinally through said drill pipe and spaced therefrom to provide an annular gas passage there-between, said tubing having a longitudinal passage opening at its bottom end to the well bore below said drill and opening at its upper end to the surface, said longitudinal passage being of substantially smaller orifice than the annular passage of the well bore about the drill pipe whereby air introduced at low pressure into the well bore at the surface llows downwardly to the bottom of the well bore at a low velocity and then upwardly at an increased velocity through said longitudinal passage to transport liquids and cuttings of earth formations being penetrated by said drill to the surface; means closing the upper and lower ends of said gas passage; means for introducing gas at relatively high ypressure into the upper end of said gas passage, said drill including a body having a bottom surface and a plurality of earth fragmentin g means mounted on said body below said bottom surface for engaging the bottom of the well bore; baffle means projecting downwardly of said bottom surface and communicating the lower open end of said tubing and extending outwardly of the central axis of said drill; and means on said body for directing jets of gas from said gas passage into the well bore downwardly and in the direction of said baffle, said tubing having passages opening upwardly thereinto adjacent said drill from said gas passage, for directing gas from said passage into said tubing near said drill; and iiow control means responsive to the pressure in said passage for controlling flow of gas from said gas passage to said means for directing jets of gas and to said last mentioned passages.

13. A well apparatus for drilling a well bore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatablye drill pipe having a drill on its lower end; a tubing extending longitudinally through said drill pipe and spaced therefrom to provide an annular gas passage therebetween, said tubing having a longitudinal passage opening at its bottom end to the well bore below said drill and opening at its upper end to tre surface; means closing the upper and lower ends of said gas passage; means for introducing gas to the upper end of said gas passage; downwardly directed jet means mounted on said drill for directing jets of gas from said gas passage into the well bore below said drill downwardly toward the bottom of the well bore and toward the lower open end of said tubing; and flow directing means on the drill directing ilow of gas and cuttings upwardly into the longitudinal passage of the tubing.

14. A well apparatus for drilling a well bore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatable drill pipe having a drill on its lower end; a tubing extending longitudinally through said drill pipe and spaced therefrom to provide an annular gas passage therebetween, said tubing having a longitudinal passage opening at its bottom end to the well bore below said drill and opening at its upper end to the surface; means closing the upper and lower ends of said gas passage; said tubing having at least one flow control device connected thereto Afor controlling iiow of gas from said gas passage into said longitudinal passage and directing the flow of gas upwardly into said longitudinal passage to increase the velocity of upward flow' of fluids through said longitudinal passage; means for introducing gas to the upper end of said gas passage; and means mounted on said drill for directing jets of gas from said gas passage into the well bore below said drill downwardly toward the bottom of the well bore and toward the lower open end of said longitudinal passage.

15. A well apparatus for drilling a well bore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatable drill pipe having a drill on its lower end; a tubing extending longitudinally through said drill pipe and spaced therefrom to provide an annular gas passage therebetween, said tubing having a longitudinal passage opening at its bottom end to the well bore below said drill and opening at its upper end to the surface; means closing the upper and lower ends of said gas passage; means for introducing gas to the upper end of said gas passage; said drill including a body having a bottom surface and a plurality of earth fragmenting means mountedon said body below said bottom surface for engagement with the bottom of the well bore; a baille extending downwardly of said bottom surface and extending outwardly of the central axis of said drill from adjacent the lower end of said tubing and communicating therewith; and means on said body for directing jets of gas from said gas passage into the well bore downwardly and in the direction of said baie, said baie having a iiexible member extending downwardly thereof toward the bottom of the well bore, said baffle opening upwardly into the lower end of said longitudinal passage of said tubing and downwardly to the bottom of the well bore.

16. A well apparatus for drilling a well bore and transporting cuttings and liquids from the well bore, said apparatus including: a rotatable drill pipe having a drill on its lower end; a tubing extending longitudinally through said drill pipe and spaced therefrom to provide an annular gas passage therebetween, said tubing having a longitudinal pasage opening at its bottom end to the well bore below said drill and opening at its upper end to the surface; means closing the upper and lower ends of said gas passage; means for introducing gas to the upper end of said gas passage; said drill including Ia body having a bottom surface and a plurality of earth fragmenting means mounted on said body below said bottom surf-ace for engagement with the bottom of the well bore; aV scoop extending downwardly of said bottom surface and communicating with said longitudinal passage, said scoop opening downwardly, and a plurality of jet means communicating with said gas passage and discharging angularly downwardly for directing jets of gas from said gas passage convergently downwardly and inwardly toward said scoop to be directed thereby into the longitudinal passage of said tubing.

17. A well bore drilling apparatus including: a drill having a body securable to a drill pipe, said body having a -bottom surface; a plurality of earth engaging and fragmenting means mounted on said body and extending downwardly of said bottom surface, said body having a central aperture for receiving a tubing extendable downwardly through said drill pipe and securable to said body; a baie extending downwardly from said bottom surface of said body and communicating at one end with said central aperture and extending substantially radially outwardly therefrom toward the outer edge of the body; and means communicating with an annular passage provided by said tubing and said drill pipe for ejecting jets of gas from such passage below said bottom surface of said body downwardly and in the direction of said battle, said baie directing such gas toward said central aperture of saidbody.

References Cited UNITED STATES PATENTS 3,195,661 7/1965 Jackson et al 175--205 X 1,263,802 4/1918 Reed 175-340 2,057,691 10/1936 Ranney 175-69 X 2,167,393 7/1939 Muncy 175-71 X 2,701,122 2/1955 Grable 175-69 X 2,954,043 9/1960 Canalizo 137-525 X 3,077,358 2/1963 Costa 175-324 X 3,095,052 6/1963 Jackson 175-324 3,169,587 2/1965 Hubbard 175-71 X 3,216,512 11/1965 Grable 175e-71 FOREIGN PATENTS 1,184,990 2/1959 France. 1,060,817 7/1959 Germany.

CHARLES E. OCONNELL, Primary Examiner.

IAN A. CALVERT, Assistant Examiner, 

13. A WELL APPARATUS FOR DRILLING A WELL BORE AND TRANSPORTING CUTTINGS AND LIQUIDS FROM THE WELL BORE, SAID APPARATUS INCLUDING: A ROTATABLY DRILL PIPE HAVING A DRILL ON ITS LOWER END; A TUBING EXTENDING LONGITUDINALLY THROUGH SAID DRILL PIPE AND SPACED THEREFROM TO PROVIDE AN ANNULAR GAS PASSAGE THEREBETWEEN, SAID TUBING HAVING A LONGITUDINAL PASSAGE OPENING AT ITS BOTTOM END TO THE WELL BORE BELOW SAID DRILL AND OPENING AT ITS UPPER END TO TRE SURFACE; MEANS CLOSING THE UPPER AND LOWER ENDS OF SAID GAS PASSAGE; MEANS FOR INTRODUCING GAS TO THE UPPER END OF SAID GAS PASSAGE; DOWNWARDLY DIRECTED JET MEANS MOUNTED ON SAID DRILL FOR DIRECTING JETS OF GAS FROM SAID GAS PASSAGE INTO THE WELL BORE BELOW SAID DRILL DOWNWARDLY TOWARD THE BOTTOM OF THE WELL BORE AND TOWARD THE LOWER OPEN END OF SAID TUBING; AND FLOW DIRECTING MEANS ON THE DRILL DIRECTING FLOW OF GAS AND CUTTINGS UPWARDLY INTO THE LONGITUDINAL PASSAGE OF THE TUBING. 